Technical Field
The present invention relates to an electrohydraulic forming device.
Description of the Related Art
Processes for manufacturing parts by hydroforming have been used over the past ten years or so in many industries. In fact, thanks to changes in these manufacturing processes, it is now possible to obtain mechanical parts in relatively complex shapes with competitive production costs. Therefore, the automobile and aeronautics industries, for example, use such technologies.
Such a hydroforming process is a process for manufacturing by deformation. It enables the plastic deformation of metal parts with a relatively thin thickness. To carry out this deformation, a fluid is used that enables the deformation of said part on a mold when the fluid is pressurized. Several techniques are used to pressurize the fluid.
One of the processes used is a process called electrohydraulic forming. This process is based on the principle of an electric discharge in the fluid stored in a tank. The amount of electrical energy released produces a shock wave whose propagation in the fluid is very fast and which enables the plastic deformation of the mechanical part against the mold. Electrodes positioned in the fluid thus release the electric charge stored in the energy storage capacitors.
U.S. Pat. No. 6,591,649 presents an electrohydraulic forming device. This device comprises a tank suitable for containing a fluid, a part to be deformed, and a set of electrodes coupled to an electric energy storage device suitable for generating a shock wave. During production phases, this shock wave, which has a relatively strong force, can cause problems with faults on certain parts of the electrohydraulic forming device.
U.S. Pat. No. 3,214,950 presents an apparatus for the deformation of metal sheets and preformed parts under the effect of a shock in water. The deformation is carried out by pressure using shock waves transmitted by the water onto the part to be deformed in a vacuum space of a hollow mold. The apparatus comprises a water container sunk into the ground, a hollow mold and a support frame for an explosive charge. The water tank also comprises a wall composed of U-bolts held together by means of a band at their upper ends and cast in concrete at their lower ends. To protect the tank from shocks, a lower part of the tank is covered in an absorbent material. The use of U-bolts cast in concrete therefore secures the device during the explosion.
In order to generate the shock wave, the electrodes, mold and the part to be deformed are generally positioned at the bottom of the tank and are thus immersed in fluid. Thus, every time the part is changed, the operator must change the part to be formed in a liquid environment.